Fix #3568: Pod upload file fails if file is directly in root path

Pod file upload seems be be creating invalid exec command for upload if
the file is directly in root path e.g. `/cp.log`. We create parent
directory of file by creating a substring based on last index of `/`.
This returns an empty string for a string like `/cp.log`.

Assume directory path to be `/` when directory is returned as empty string.

Signed-off-by: Rohan Kumar <rohaan@redhat.com>

CHANGELOG.md

@@ -10,6 +10,7 @@
 * Fix #3588: `openshift-server-mock` is not listed in dependencyManagement in main pom
 * Fix #3679: output additionalProperties field with correct value type for map-like fields (CRD Generator)
 * Fix #3648: `Serialization.unmarshal` fails to deserialize YAML with single document in presence of document delimiter(`---`)
+* Fix #3568: Pod file upload fails if the path is `/`
 
 #### Improvements
 * Fix #3674: allows the connect and websocket timeouts to apply to watches instead of a hardcoded timeout

kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/internal/uploadable/PodUpload.java

@@ -73,13 +73,8 @@ public static boolean upload(HttpClient client, PodOperationContext context,
   private static boolean uploadFile(HttpClient client, PodOperationContext context,
     OperationSupport operationSupport, Path pathToUpload)
     throws IOException, InterruptedException {
-
-    final String file = context.getFile();
-    final String directory = file.substring(0, file.lastIndexOf('/'));
-    final String command = String.format(
-      "mkdir -p %s && base64 -d - > %s", shellQuote(directory), shellQuote(file));
     final PodUploadWebSocketListener podUploadWebSocketListener = initWebSocket(
-      buildCommandUrl(command, context, operationSupport), client);
+      buildCommandUrl(createExecCommandForUpload(context), context, operationSupport), client);
     try (
       final FileInputStream fis = new FileInputStream(pathToUpload.toFile());
       final Base64.InputStream b64In = new Base64.InputStream(fis, Base64.ENCODE)
@@ -193,4 +188,12 @@ private static URL buildCommandUrl(String command, PodOperationContext context,
     return new URL(
       URLUtils.join(operationSupport.getResourceUrl().toString(), commandBuilder.toString()));
   }
+
+  static String createExecCommandForUpload(PodOperationContext context) {
+    final String file = context.getFile();
+    String directoryTrimmedFromFilePath = file.substring(0, file.lastIndexOf('/'));
+    final String directory = directoryTrimmedFromFilePath.isEmpty() ? "/" : directoryTrimmedFromFilePath;
+    return String.format(
+      "mkdir -p %s && base64 -d - > %s", shellQuote(directory), shellQuote(file));
+  }
 }

kubernetes-client/src/test/java/io/fabric8/kubernetes/client/dsl/internal/uploadable/PodUploadTest.java

@@ -80,7 +80,7 @@ void tearDown() {
   }
 
   @Test
-  void testUploadInvalidParametersShouldThrowException() throws Exception {
+  void testUploadInvalidParametersShouldThrowException() {
     final IllegalArgumentException result = assertThrows(IllegalArgumentException.class,
       () -> PodUpload.upload(mockClient, mockContext, operationSupport, mockPathToUpload));
 
@@ -171,4 +171,28 @@ void testCopy() throws Exception {
     PodUpload.copy(input, consumer);
   }
 
+  @Test
+  void createExecCommandForUpload_withFileInRootPath_shouldCreateValidExecCommandForUpload() {
+    // Given
+    when(mockContext.getFile()).thenReturn("/cp.log");
+
+    // When
+    String result = PodUpload.createExecCommandForUpload(mockContext);
+
+    // Then
+    assertThat(result, equalTo("mkdir -p '/' && base64 -d - > '/cp.log'"));
+  }
+
+  @Test
+  void createExecCommandForUpload_withNormalFile_shouldCreateValidExecCommandForUpload() {
+    // Given
+    when(mockContext.getFile()).thenReturn("/tmp/foo/cp.log");
+
+    // When
+    String result = PodUpload.createExecCommandForUpload(mockContext);
+
+    // Then
+    assertThat(result, equalTo("mkdir -p '/tmp/foo' && base64 -d - > '/tmp/foo/cp.log'"));
+  }
+
 }